1. Field of the Invention
The present invention relates to an automatic analysis apparatus like a biochemical analysis apparatus in which a sample such as blood or urine is spotted onto a calorimetric dry analysis element or an electrolytic dry analysis element, and the concentration, ion activity and the like of a specific biochemical component contained in the sample are determined. The present invention particularly relates to a mechanism for correcting the position of a dry analysis element contained in an element cartridge.
2. Description of the Related Art
Traditionally, there have been developed and practically implemented colorimetric dry analysis elements with which the content of a specific biochemical component or specific solid component contained in a sample can be quantitatively analyzed by merely spotting a droplet of the sample, and electrolytic dry analysis elements with which the activity of a specific ion contained in a sample can be determined by merely spotting a droplet of the sample. The biochemical analysis apparatuses using such dry analysis elements are preferably used in medical institutions, laboratories and the like owing to their capability of analyzing samples easily and quickly.
The colorimetry method using calorimetric dry analysis elements is as follows: a droplet of a sample is spotted on a dry analysis element; the analysis element is held at a constant temperature for a predetermined time in an incubator so that a coloring reaction (pigment forming reaction) occurs; the optical density of the color formed by the coloring reaction is optically measured by exposing the analysis element to measuring light, containing a wavelength which is pre-selected according to the combination of the component to be analyzed and the reagent contained in the analysis element; and the concentration of the component to be analyzed is determined on the basis of the optical density according to a calibration curve representing the relationship between the concentration of the specific biochemical component and the optical density.
On the other hand, in the potentiometry method using an electrolytic dry analysis element, the activity of a specific ion contained in a sample spotted on an ion selective electrode pair of a dry analysis element is potentiometrically measured instead of measuring the optical density.
In either of colorimetry or potentiometry, the sample is contained in a sample container (e.g., a blood-collecting tube) and set in the analysis apparatus, while an analysis element required for the measurement is loaded in the apparatus. The dry analysis element is carried from the loaded position to a spotting position while the sample is delivered by a spotting nozzle from the set position to the spotting position for spotting on the dry analysis element.
In the biochemical analysis apparatus, a plurality of dry analysis elements as mentioned above for measuring the same or different items are contained in a stacked form in element cartridges, and such element cartridges are set in a sample tray. Then, a cartridge containing therein desired dry analysis elements is moved to a predetermined element-takeout position by the linear and rotational movement of the sample tray. F Thereby the desired dry analysis elements are removed out of this element cartridge and conveyed to a spotting station. Examples of such known element cartridges include those provided for horizontally moving the lowermost dry analysis element, for example, by a transfer bar, and taking the element out of a take-out port provided in the lower portion of the sidewall, in order to make the takeout position constant (see U.S. Patent Laid-Open Nos. 20020031844 and 20020098116.)
For the element cartridge holding therein dry analysis elements as mentioned above, a problem may arise in association with the fact that the lowermost dry analysis element is movable to project outward from the element take-out port.
More specifically, when handling the element cartridge for the purpose of loading the dry analysis elements into the element cartridge, setting the element cartridge holding therein the dry analysis elements in the sample tray or the like, are loaded in the element cartridge, the lowermost dry analysis element within the cartridge may unintentionally penetrate into the element take-out port or protrude outward therefrom. Consequently, such displacement of the dry analysis element could cause conveyance failure and/or information readout failure. For example, some dry analysis elements carry on their bottom surfaces analysis information including the measuring items and the like, and such analysis information is read out before removing the dry analysis element to be used for measurement control. In the case that the dry analysis element is displaced as mentioned above, the analysis information recorded on the bottom surface thereof cannot be read properly, and may also cause trouble in the conveyance of the element.